Let solar be the source

Commenting on the judicial review of 15 February that threw out the UK government’s plans to build more nuclear power stations, the DTI and Tony Blair have both stressed the importance of energy security. But is that security provided by nuclear ?

Commenting on the judicial review of 15 February that threw out the UK government’s plans to build more nuclear power stations (The Engineer Online, 15 February), the DTI and Tony Blair have both stressed the importance of energy security. But is that security provided by nuclear ?

First, all the raw material, uranium, needed for UK nuclear power is imported from politically unstable countries, so supplies cannot be guaranteed.

As exploitable sources become exhausted, prices will rise. And as higher-grade ores run out, more energy will be consumed and more CO2 will be released in processing the lower-grade material that remains.

Second, just like wind power and other sources of electricity, nuclear power is available intermittently. Power stations stop producing electricity during routine maintenance and unscheduled breakdowns and the ‘load factor’ — the electricity produced compared with the theoretical maximum — is normally well short of 100 per cent.

Then there is the risk of flooding. All of the UK’s 15 nuclear plants are near the coast and British Energy research suggests that ‘nuclear stations on the UK coast will experience storm surges up to 1.7m (over 5ft) higher by 2080 because of global warming’.

And far from being low-carbon, nuclear power is a major source of emissions. Even under the most favourable conditions, plants produce approximately one third as much CO2 as gas-fired electricity production.

Using the richest ores available, a nuclear plant must operate for 10 years at full load before it has generated more energy than was consumed in mining and refining the uranium, building the plant and so on.

The DTI says a balanced approach is needed, involving renewables and other low-carbon sources. Instead of trying to keep the nuclear industry afloat, our taxes should go on energising the renewables market.

As well as local UK projects like on- and off-shore wind power, we should be looking seriously at a solar technology called Concentrating Solar Power (CSP).

This uses the sun’s heat to produce steam and turn turbines like a conventional power station. It is also possible to store solar heat in melted salts so that electricity generation can continue throughout the night or on cloudy days. This technology has worked successfully for half a million Californians since 1985 and plants are being planned or built around the world.

Although the system works best in hot deserts, it is feasible and economical to transmit solar electricity over long distances using highly-efficient ‘HVDC’ transmission lines.

In a report commissioned by the German government it is estimated that CSP electricity, imported from north Africa and the middle east, could become one of Europe’s cheapest sources of electricity.

Robert Palgrave

Woking, Surrey

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